SU31508A1 - Method and device for measuring time intervals - Google Patents

Description

Dumps are already known for measuring promissory time by observing the magnitude of the potential difference across the capacitor plates charged by the saturation current 4 of the cathode lamina. The value of the time interval is determined by the formula

with

 -7- where E is the potential difference

capacitor plates, 4 is the saturation current. (The method proposed by Buge, Archiv fur Electrotechnik, Vol XVIII No. 6, 1927).

The essence of the invention is that the control of switching on and off the circuit that charges the capacitor is made by abruptly changing the sign of the potential imparted to the electrode of the cathode lamp by means of a switch that turns off the potentiometer, the slider of which is connected to the cathode of the lamp so that when the switch is open Negative charge from the potentiometer point was reported to the lamp electrode through the resistance and the relay coil; when the switch was closed, the positive was reported to the grid. potential from another point of the potentiometer, and the current passed to the capacitor. .

In FIG. 1 shows a diagram of an apparatus for carrying out the proposed method; FIG. 2-second option for the same purpose.

In the anode circuit of the cathode lamp G (Fig. 1), which controls the charge of the capacitor .6, the latter is connected in series with the firing contacts / C of the tested relay R. The saturation tone of the lamp can be measured by device A. At the same time, the capacitor b and contacts K can be shunted with a switch - a key 2. The magnitude of the potentials on the capacitor plates Q is measured by an instrument / 2, for example, of an electrostatic system.

The control system for the supply of potentials of a different sign on, the grid of the cathode lamp cred / is found in a particular inclusion of the different; whose: points of the AC potentiometer. Point C of potentiometer AC is connected to the grid of the lamp through the winding of the tested relay P and measuring instrument L, while the other point L, having the opposite sign of potential, can be connected to the grid of the lamp by means of a switch / simultaneously with the connection of the test relay to the winding.

The formula from which the time interval is determined includes the quantity

saturation current 4 A preliminary determination of this value is made as follows. Point MI has a positive potential, M. - negative; key 2, shunt capacitor 6 ti k is closed. Locking key /, impose a positive potential on the grid. By adjusting slider B, it is possible to change the value of the supplied Vg. On the device And notice the value / d in area 4.

Later, if necessary, before measurements by means of the switch G /, alternating current of diminishing amplitude is supplied to the relay to demagnetize it, after which the switch is again set to the previous position. Key 4 is closed so that the capacitor is discharged immediately before the measurement.

To measure the response time of the relay, key 4 is opened and immediately closed the key /. By this, on the grid, the voltage that changes the sign of the negative is sharply changed, the negative becomes positive. The anode current begins to charge the capacitor Q until the contacts K are open. Using the device V2, note the potential difference Ef, on the plates of the capacitor C and calculate the value of the time interval

with Eg according to the formula t

s

When measuring the release time of the relay contacts, the point MI is connected to the negative pole of the battery, point F, to the positive.

Splitting key /, impose a positive potential on the grid. Key 3 is open. By moving the slider B, you can adjust the amount of superimposed Vg. The lock key 2, note the value of the saturation current Ig, Close the key 4 and open the key 2, then close the key /. The grid is now negative voltage. In order to measure the lowering time, open the key / and note through the device V the potential difference E on the plates of capacitor C. From the moment the key 2 is opened until the contacts of the AH break, the capacitor is charged with an anode current.

The time is calculated using the formula already given.

When measuring the release time on the grid circuit (with open key 7), a positive potential difference of CSS is superimposed corresponding to points C to B. Some of the voltage is lost along the resistance in the grid circuit, so that 1 / меньше is less than VQJJ. In order to always be able to impose the desired magnitude of the voltage Vg on the grid, it is proposed to use the following technique. Key 7 opens, key 3 closes. This shunts the resistance of the grid circuit and the voltage 1/3 (7 superimposes directly on the grid. Note the value of saturation current 4 - l4- Moving the slider B, increase Vg so that the previous value of 4 is obtained and, therefore, the desired value V.

In FIG. Figure 2 shows a diagram of an apparatus which makes it possible to carry out various measurement methods and therefore is more versatile. The scheme includes: a potentiometer consisting of two adjustable resistances, RU, connected to the terminals NI, N.2, current sources, as well as switches P and / 4 and keys 7-W, 12 - 76, by means of which all necessary switching relays P, contacts LG, batteries E, B and measuring instruments Vi, C and AI, Lo.

The breaker keys 72, 75, J4, 9 and 10, the lock keys 8, 77, 75, 75i, 16, are able to make all the measurements of the response and release times, which were made by the device according to the diagram of FIG. 1 in all cases where the measured period of time ends at the moment of opening the contacts. In this case, the relay is connected to points Xi and X, and its fencing contacts to points Yi and Y.2. The voltage in this case is the same as in the diagram of FIG. 1 is supplied to the points MI and M ,, (or Xi and. A significant feature of the device of Fig. 2, as compared with the circuit of Fig. 1, is the ability to measure the response and release times with it also when measurable gap

time ends at the moment of closing (and not opening, as before) contacts. In the case of measuring the response time when the contacts are closed, the relay circuit is connected to the points and and and (or to / 7 / and and., The group contacts to the points Zj and Z., To the point L., the positive pole of the battery is fed, L, negative. The /, 12, 13, 14, and 10 keys are closed, and 8, 11, 15, and 16 are opened. Through a switch, a millimeter per meter is introduced into the ABC relay circuit. By means of the jBo battery, some negative voltage is applied to the lamp. .

The response time is measured as follows. Preliminary measurements and calibration of the positive voltage supplied to the anode by the shunt CC, is performed in the same way as in the described device. Before the start of the measurement, the switch 9 is open and, consequently, a negative potential (imposed by the battery) at the anode. At the moment of starting the measurement, the key 9 is closed (the contact / Ca is open) and a positive potential is applied to the anode. At the moment of the relay / contact actuation, the Sz shuts off to the anode abruptly, abruptly, through Sz an additional negative potential is applied, blocking the anode current, and consequently, the increase in the potential difference across the capacitor plates simultaneously stops.

Measurement of the release time in the case when the measured period of time ends with the closure of the contacts of the group (after breaking the value of the relay) is carried out as follows. The relay is connected to points i and AZ, and its fencing contacts (initially open) to points Zi and Z. To the point G, (or) the positive pole of the power supply, and to the point MI (or NI) is negative. The battery DB, if desired, imposes an additional negative potential on the anode or is completely turned off (by closing the // key and opening the key / 2). Keys 5, 13 and 14 are open all the time, keys /, 10, 15, / 5, and 16 are closed all the time. A switch 712 introduces a milliammeter into the relay circuit PI. And the resistance RI.

Prior to measurement, switch 8 is closed, and therefore, a negative potential is applied to the anode, respectively. The start of measurement, switch 8 is opened and a positive potential Kg (;, corresponding to the potential drop along the resistance between points B and C is applied to the anode. When the relay is released, contacts K The negative potential of the high frequency pfg is closed and again on the anode - filament, as a result of which the anode current of the lamp stops (at the corresponding absolute value of negative 1 /).

The subject matter of the invention.

Claims (3)

1. Method for measuring time intervals by changing the magnitude of the potential difference on the plates of a capacitor switched on at the time of the beginning of the measured period of time in an electrical circuit and switched off at its end, using a cathode lamp as a valve device, controlling its capacitor charge characterized in that the on / off control of the circuit that charges the capacitor is controlled by abruptly changing the sign of the potential imparted to the Electrode of the cathode lamp by means of a switch l /, turning off the potentiometer AC, the slider B of which is connected to the cathode of the lamp so that when the switch / lamp electrode is open a negative charge from the LG point of the potentiometer is reported through the resistance R and the winding of the relay P, when the switch / grid is closed, positive potential from point M potentiometer and the current passed into the capacitor Q. 2. Devices for carrying out the method according to claim 1, characterized in that in order to be able to carry out various measuring methods, a potentiometer consisting of two adjustable resistances, R; attached to the current source NI, N, is used. adjustable resistances Ri Ri, R, as well as switches IJi, Sch, Sch, and switches 1-10, 12-16, by which all necessary switchings of relays P, contacts K, batteries Bz, B., and measuring instruments UB V2, A, and L2 are made. 3. With the device according to claim 2, the use of a two- or multi-electrode: a lamp to control the charge of the capacitor. fig /;